1 /* $FreeBSD: src/sys/netinet6/ip6_input.c,v 1.11.2.15 2003/01/24 05:11:35 sam Exp $ */ 2 /* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 62 */ 63 64 #include "opt_ip6fw.h" 65 #include "opt_inet.h" 66 #include "opt_inet6.h" 67 #include "opt_ipsec.h" 68 69 #include <sys/param.h> 70 #include <sys/systm.h> 71 #include <sys/malloc.h> 72 #include <sys/mbuf.h> 73 #include <sys/domain.h> 74 #include <sys/protosw.h> 75 #include <sys/socket.h> 76 #include <sys/socketvar.h> 77 #include <sys/errno.h> 78 #include <sys/time.h> 79 #include <sys/kernel.h> 80 #include <sys/syslog.h> 81 #include <sys/proc.h> 82 #include <sys/priv.h> 83 84 #include <net/if.h> 85 #include <net/if_types.h> 86 #include <net/if_dl.h> 87 #include <net/route.h> 88 #include <net/netisr.h> 89 #include <net/pfil.h> 90 91 #include <sys/thread2.h> 92 #include <sys/msgport2.h> 93 #include <net/netmsg2.h> 94 #include <net/netisr2.h> 95 96 #include <netinet/in.h> 97 #include <netinet/in_systm.h> 98 #ifdef INET 99 #include <netinet/ip.h> 100 #include <netinet/ip_icmp.h> 101 #endif /* INET */ 102 #include <netinet/ip6.h> 103 #include <netinet6/in6_var.h> 104 #include <netinet6/ip6_var.h> 105 #include <netinet/in_pcb.h> 106 #include <netinet/icmp6.h> 107 #include <netinet6/scope6_var.h> 108 #include <netinet6/in6_ifattach.h> 109 #include <netinet6/nd6.h> 110 111 #ifdef IPSEC 112 #include <netinet6/ipsec.h> 113 #ifdef INET6 114 #include <netinet6/ipsec6.h> 115 #endif 116 #endif 117 118 #ifdef FAST_IPSEC 119 #include <netproto/ipsec/ipsec.h> 120 #include <netproto/ipsec/ipsec6.h> 121 #define IPSEC 122 #endif /* FAST_IPSEC */ 123 124 #include <net/ip6fw/ip6_fw.h> 125 126 #include <netinet6/ip6protosw.h> 127 128 #include <net/net_osdep.h> 129 130 extern struct domain inet6domain; 131 extern struct protosw inet6sw[]; 132 133 u_char ip6_protox[IPPROTO_MAX]; 134 struct in6_ifaddr *in6_ifaddr; 135 136 int ip6_forward_srcrt; /* XXX */ 137 int ip6_sourcecheck; /* XXX */ 138 int ip6_sourcecheck_interval; /* XXX */ 139 140 int ip6_ours_check_algorithm; 141 142 struct pfil_head inet6_pfil_hook; 143 144 /* firewall hooks */ 145 ip6_fw_chk_t *ip6_fw_chk_ptr; 146 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 147 int ip6_fw_enable = 1; 148 149 struct ip6stat ip6stat; 150 151 static void ip6_init2 (void *); 152 static struct ip6aux *ip6_setdstifaddr (struct mbuf *, struct in6_ifaddr *); 153 static int ip6_hopopts_input (u_int32_t *, u_int32_t *, struct mbuf **, int *); 154 static void ip6_input(netmsg_t msg); 155 #ifdef PULLDOWN_TEST 156 static struct mbuf *ip6_pullexthdr (struct mbuf *, size_t, int); 157 #endif 158 static void transport6_processing_handler(netmsg_t netmsg); 159 160 /* 161 * IP6 initialization: fill in IP6 protocol switch table. 162 * All protocols not implemented in kernel go to raw IP6 protocol handler. 163 */ 164 void 165 ip6_init(void) 166 { 167 struct protosw *pr; 168 int i; 169 struct timeval tv; 170 171 pr = pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 172 if (pr == NULL) 173 panic("ip6_init"); 174 for (i = 0; i < IPPROTO_MAX; i++) 175 ip6_protox[i] = pr - inet6sw; 176 for (pr = inet6domain.dom_protosw; 177 pr < inet6domain.dom_protoswNPROTOSW; pr++) 178 if (pr->pr_domain->dom_family == PF_INET6 && 179 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 180 ip6_protox[pr->pr_protocol] = pr - inet6sw; 181 182 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 183 inet6_pfil_hook.ph_af = AF_INET6; 184 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) { 185 kprintf("%s: WARNING: unable to register pfil hook, " 186 "error %d\n", __func__, i); 187 } 188 189 netisr_register(NETISR_IPV6, ip6_input, NULL); /* XXX hashfn */ 190 scope6_init(); 191 addrsel_policy_init(); 192 nd6_init(); 193 frag6_init(); 194 /* 195 * in many cases, random() here does NOT return random number 196 * as initialization during bootstrap time occur in fixed order. 197 */ 198 microtime(&tv); 199 ip6_flow_seq = krandom() ^ tv.tv_usec; 200 microtime(&tv); 201 ip6_desync_factor = (krandom() ^ tv.tv_usec) % MAX_TEMP_DESYNC_FACTOR; 202 } 203 204 static void 205 ip6_init2(void *dummy) 206 { 207 nd6_timer_init(); 208 in6_tmpaddrtimer_init(); 209 } 210 211 /* cheat */ 212 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 213 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 214 215 extern struct route_in6 ip6_forward_rt; 216 217 static void 218 ip6_input(netmsg_t msg) 219 { 220 struct mbuf *m = msg->packet.nm_packet; 221 struct ip6_hdr *ip6; 222 int off = sizeof(struct ip6_hdr), nest; 223 u_int32_t plen; 224 u_int32_t rtalert = ~0; 225 int nxt, ours = 0, rh_present = 0; 226 struct ifnet *deliverifp = NULL; 227 struct in6_addr odst; 228 int srcrt = 0; 229 230 #ifdef IPSEC 231 /* 232 * should the inner packet be considered authentic? 233 * see comment in ah4_input(). 234 */ 235 if (m) { 236 m->m_flags &= ~M_AUTHIPHDR; 237 m->m_flags &= ~M_AUTHIPDGM; 238 } 239 #endif 240 241 /* 242 * make sure we don't have onion peering information into m_aux. 243 */ 244 ip6_delaux(m); 245 246 /* 247 * mbuf statistics 248 */ 249 if (m->m_flags & M_EXT) { 250 if (m->m_next) 251 ip6stat.ip6s_mext2m++; 252 else 253 ip6stat.ip6s_mext1++; 254 } else { 255 #define M2MMAX NELEM(ip6stat.ip6s_m2m) 256 if (m->m_next) { 257 if (m->m_flags & M_LOOP) { 258 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 259 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 260 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 261 else 262 ip6stat.ip6s_m2m[0]++; 263 } else 264 ip6stat.ip6s_m1++; 265 #undef M2MMAX 266 } 267 268 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 269 ip6stat.ip6s_total++; 270 271 #ifndef PULLDOWN_TEST 272 /* 273 * L2 bridge code and some other code can return mbuf chain 274 * that does not conform to KAME requirement. too bad. 275 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 276 */ 277 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 278 struct mbuf *n; 279 280 n = m_getb(m->m_pkthdr.len, M_NOWAIT, MT_HEADER, M_PKTHDR); 281 if (n == NULL) 282 goto bad; 283 M_MOVE_PKTHDR(n, m); 284 285 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 286 n->m_len = n->m_pkthdr.len; 287 m_freem(m); 288 m = n; 289 } 290 IP6_EXTHDR_CHECK_VOIDRET(m, 0, sizeof(struct ip6_hdr)); 291 #endif 292 293 if (m->m_len < sizeof(struct ip6_hdr)) { 294 struct ifnet *inifp; 295 inifp = m->m_pkthdr.rcvif; 296 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 297 ip6stat.ip6s_toosmall++; 298 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 299 goto bad2; 300 } 301 } 302 303 ip6 = mtod(m, struct ip6_hdr *); 304 305 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 306 ip6stat.ip6s_badvers++; 307 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 308 goto bad; 309 } 310 311 /* 312 * Run through list of hooks for input packets. 313 * 314 * NB: Beware of the destination address changing 315 * (e.g. by NAT rewriting). When this happens, 316 * tell ip6_forward to do the right thing. 317 */ 318 if (pfil_has_hooks(&inet6_pfil_hook)) { 319 odst = ip6->ip6_dst; 320 if (pfil_run_hooks(&inet6_pfil_hook, &m, 321 m->m_pkthdr.rcvif, PFIL_IN)) { 322 goto bad2; 323 } 324 if (m == NULL) /* consumed by filter */ 325 goto bad2; 326 ip6 = mtod(m, struct ip6_hdr *); 327 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 328 } 329 330 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 331 332 #ifdef ALTQ 333 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 334 /* packet is dropped by traffic conditioner */ 335 return; 336 } 337 #endif 338 339 /* 340 * Check with the firewall... 341 */ 342 if (ip6_fw_enable && ip6_fw_chk_ptr) { 343 u_short port = 0; 344 /* If ipfw says divert, we have to just drop packet */ 345 /* use port as a dummy argument */ 346 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 347 m_freem(m); 348 m = NULL; 349 } 350 if (!m) 351 goto bad2; 352 } 353 354 /* 355 * Check against address spoofing/corruption. 356 */ 357 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 358 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 359 /* 360 * XXX: "badscope" is not very suitable for a multicast source. 361 */ 362 ip6stat.ip6s_badscope++; 363 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 364 goto bad; 365 } 366 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 367 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 368 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 369 ip6stat.ip6s_badscope++; 370 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 371 goto bad; 372 } 373 374 /* 375 * The following check is not documented in specs. A malicious 376 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 377 * and bypass security checks (act as if it was from 127.0.0.1 by using 378 * IPv6 src ::ffff:127.0.0.1). Be cautious. 379 * 380 * This check chokes if we are in an SIIT cloud. As none of BSDs 381 * support IPv4-less kernel compilation, we cannot support SIIT 382 * environment at all. So, it makes more sense for us to reject any 383 * malicious packets for non-SIIT environment, than try to do a 384 * partial support for SIIT environment. 385 */ 386 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 387 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 388 ip6stat.ip6s_badscope++; 389 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 390 goto bad; 391 } 392 #if 0 393 /* 394 * Reject packets with IPv4 compatible addresses (auto tunnel). 395 * 396 * The code forbids auto tunnel relay case in RFC1933 (the check is 397 * stronger than RFC1933). We may want to re-enable it if mech-xx 398 * is revised to forbid relaying case. 399 */ 400 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 401 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 402 ip6stat.ip6s_badscope++; 403 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 404 goto bad; 405 } 406 #endif 407 408 /* drop packets if interface ID portion is already filled */ 409 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 410 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 411 ip6->ip6_src.s6_addr16[1]) { 412 ip6stat.ip6s_badscope++; 413 goto bad; 414 } 415 if ((IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) || 416 IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) && 417 ip6->ip6_dst.s6_addr16[1]) { 418 ip6stat.ip6s_badscope++; 419 goto bad; 420 } 421 } 422 423 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 424 ip6->ip6_src.s6_addr16[1] 425 = htons(m->m_pkthdr.rcvif->if_index); 426 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 427 ip6->ip6_dst.s6_addr16[1] 428 = htons(m->m_pkthdr.rcvif->if_index); 429 430 /* 431 * Multicast check 432 * 433 * WARNING! For general subnet proxying the interface hw will 434 * likely filter out the multicast solicitations, so 435 * the interface must be in promiscuous mode. 436 */ 437 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 438 ours = 1; 439 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 440 deliverifp = m->m_pkthdr.rcvif; 441 goto hbhcheck; 442 } 443 444 /* 445 * Unicast check 446 */ 447 if (ip6_forward_rt.ro_rt != NULL && 448 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) && 449 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 450 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) { 451 ip6stat.ip6s_forward_cachehit++; 452 } else { 453 struct sockaddr_in6 *dst6; 454 455 if (ip6_forward_rt.ro_rt) { 456 /* route is down or destination is different */ 457 ip6stat.ip6s_forward_cachemiss++; 458 RTFREE(ip6_forward_rt.ro_rt); 459 ip6_forward_rt.ro_rt = 0; 460 } 461 462 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 463 dst6 = &ip6_forward_rt.ro_dst; 464 dst6->sin6_len = sizeof(struct sockaddr_in6); 465 dst6->sin6_family = AF_INET6; 466 dst6->sin6_addr = ip6->ip6_dst; 467 468 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 469 } 470 471 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 472 473 /* 474 * Accept the packet if the forwarding interface to the destination 475 * according to the routing table is the loopback interface, 476 * unless the associated route has a gateway. 477 * Note that this approach causes to accept a packet if there is a 478 * route to the loopback interface for the destination of the packet. 479 * But we think it's even useful in some situations, e.g. when using 480 * a special daemon which wants to intercept the packet. 481 * 482 * XXX: some OSes automatically make a cloned route for the destination 483 * of an outgoing packet. If the outgoing interface of the packet 484 * is a loopback one, the kernel would consider the packet to be 485 * accepted, even if we have no such address assinged on the interface. 486 * We check the cloned flag of the route entry to reject such cases, 487 * assuming that route entries for our own addresses are not made by 488 * cloning (it should be true because in6_addloop explicitly installs 489 * the host route). However, we might have to do an explicit check 490 * while it would be less efficient. Or, should we rather install a 491 * reject route for such a case? 492 */ 493 if (ip6_forward_rt.ro_rt && 494 (ip6_forward_rt.ro_rt->rt_flags & 495 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 496 #ifdef RTF_WASCLONED 497 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 498 #endif 499 #ifdef RTF_CLONED 500 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 501 #endif 502 #if 0 503 /* 504 * The check below is redundant since the comparison of 505 * the destination and the key of the rtentry has 506 * already done through looking up the routing table. 507 */ 508 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 509 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 510 #endif 511 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 512 struct in6_ifaddr *ia6 = 513 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 514 515 /* 516 * record address information into m_aux. 517 */ 518 ip6_setdstifaddr(m, ia6); 519 520 /* 521 * packets to a tentative, duplicated, or somehow invalid 522 * address must not be accepted. 523 */ 524 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 525 /* this address is ready */ 526 ours = 1; 527 deliverifp = ia6->ia_ifp; /* correct? */ 528 /* Count the packet in the ip address stats */ 529 IFA_STAT_INC(&ia6->ia_ifa, ipackets, 1); 530 IFA_STAT_INC(&ia6->ia_ifa, ibytes, m->m_pkthdr.len); 531 goto hbhcheck; 532 } else { 533 /* address is not ready, so discard the packet. */ 534 nd6log((LOG_INFO, 535 "ip6_input: packet to an unready address %s->%s\n", 536 ip6_sprintf(&ip6->ip6_src), 537 ip6_sprintf(&ip6->ip6_dst))); 538 539 goto bad; 540 } 541 } 542 543 /* 544 * FAITH (Firewall Aided Internet Translator) 545 */ 546 if (ip6_keepfaith) { 547 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 548 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 549 /* XXX do we need more sanity checks? */ 550 ours = 1; 551 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 552 goto hbhcheck; 553 } 554 } 555 556 /* 557 * Now there is no reason to process the packet if it's not our own 558 * and we're not a router. 559 */ 560 if (!ip6_forwarding) { 561 ip6stat.ip6s_cantforward++; 562 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 563 goto bad; 564 } 565 566 hbhcheck: 567 /* 568 * record address information into m_aux, if we don't have one yet. 569 * note that we are unable to record it, if the address is not listed 570 * as our interface address (e.g. multicast addresses, addresses 571 * within FAITH prefixes and such). 572 */ 573 if (deliverifp && !ip6_getdstifaddr(m)) { 574 struct in6_ifaddr *ia6; 575 576 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 577 if (ia6) { 578 if (!ip6_setdstifaddr(m, ia6)) { 579 /* 580 * XXX maybe we should drop the packet here, 581 * as we could not provide enough information 582 * to the upper layers. 583 */ 584 } 585 } 586 } 587 588 /* 589 * Process Hop-by-Hop options header if it's contained. 590 * m may be modified in ip6_hopopts_input(). 591 * If a JumboPayload option is included, plen will also be modified. 592 */ 593 plen = (u_int32_t)ntohs(ip6->ip6_plen); 594 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 595 struct ip6_hbh *hbh; 596 597 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 598 #if 0 /*touches NULL pointer*/ 599 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 600 #endif 601 goto bad2; /* m have already been freed */ 602 } 603 604 /* adjust pointer */ 605 ip6 = mtod(m, struct ip6_hdr *); 606 607 /* 608 * if the payload length field is 0 and the next header field 609 * indicates Hop-by-Hop Options header, then a Jumbo Payload 610 * option MUST be included. 611 */ 612 if (ip6->ip6_plen == 0 && plen == 0) { 613 /* 614 * Note that if a valid jumbo payload option is 615 * contained, ip6_hoptops_input() must set a valid 616 * (non-zero) payload length to the variable plen. 617 */ 618 ip6stat.ip6s_badoptions++; 619 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 620 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 621 icmp6_error(m, ICMP6_PARAM_PROB, 622 ICMP6_PARAMPROB_HEADER, 623 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 624 goto bad2; 625 } 626 #ifndef PULLDOWN_TEST 627 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 628 hbh = (struct ip6_hbh *)(ip6 + 1); 629 #else 630 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 631 sizeof(struct ip6_hbh)); 632 if (hbh == NULL) { 633 ip6stat.ip6s_tooshort++; 634 goto bad2; 635 } 636 #endif 637 nxt = hbh->ip6h_nxt; 638 639 /* 640 * If we are acting as a router and the packet contains a 641 * router alert option, see if we know the option value. 642 * Currently, we only support the option value for MLD, in which 643 * case we should pass the packet to the multicast routing 644 * daemon. 645 */ 646 if (rtalert != ~0 && ip6_forwarding) { 647 switch (rtalert) { 648 case IP6OPT_RTALERT_MLD: 649 ours = 1; 650 break; 651 default: 652 /* 653 * RFC2711 requires unrecognized values must be 654 * silently ignored. 655 */ 656 break; 657 } 658 } 659 } else 660 nxt = ip6->ip6_nxt; 661 662 /* 663 * Check that the amount of data in the buffers 664 * is as at least much as the IPv6 header would have us expect. 665 * Trim mbufs if longer than we expect. 666 * Drop packet if shorter than we expect. 667 */ 668 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 669 ip6stat.ip6s_tooshort++; 670 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 671 goto bad; 672 } 673 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 674 if (m->m_len == m->m_pkthdr.len) { 675 m->m_len = sizeof(struct ip6_hdr) + plen; 676 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 677 } else 678 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 679 } 680 681 /* 682 * Forward if desirable. 683 */ 684 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 685 /* 686 * If we are acting as a multicast router, all 687 * incoming multicast packets are passed to the 688 * kernel-level multicast forwarding function. 689 * The packet is returned (relatively) intact; if 690 * ip6_mforward() returns a non-zero value, the packet 691 * must be discarded, else it may be accepted below. 692 */ 693 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 694 ip6stat.ip6s_cantforward++; 695 goto bad; 696 } 697 if (!ours) 698 goto bad; 699 } else if (!ours) { 700 ip6_forward(m, srcrt); 701 goto bad2; 702 } 703 704 ip6 = mtod(m, struct ip6_hdr *); 705 706 /* 707 * Malicious party may be able to use IPv4 mapped addr to confuse 708 * tcp/udp stack and bypass security checks (act as if it was from 709 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 710 * 711 * For SIIT end node behavior, you may want to disable the check. 712 * However, you will become vulnerable to attacks using IPv4 mapped 713 * source. 714 */ 715 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 716 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 717 ip6stat.ip6s_badscope++; 718 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 719 goto bad; 720 } 721 722 /* 723 * Tell launch routine the next header 724 */ 725 ip6stat.ip6s_delivered++; 726 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 727 nest = 0; 728 729 rh_present = 0; 730 while (nxt != IPPROTO_DONE) { 731 struct protosw *sw6; 732 733 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 734 ip6stat.ip6s_toomanyhdr++; 735 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 736 goto bad; 737 } 738 739 /* 740 * protection against faulty packet - there should be 741 * more sanity checks in header chain processing. 742 */ 743 if (m->m_pkthdr.len < off) { 744 ip6stat.ip6s_tooshort++; 745 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 746 goto bad; 747 } 748 749 #if 0 750 /* 751 * do we need to do it for every header? yeah, other 752 * functions can play with it (like re-allocate and copy). 753 */ 754 mhist = ip6_addaux(m); 755 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { 756 hist = mtod(mhist, caddr_t) + mhist->m_len; 757 bcopy(&nxt, hist, sizeof(nxt)); 758 mhist->m_len += sizeof(nxt); 759 } else { 760 ip6stat.ip6s_toomanyhdr++; 761 goto bad; 762 } 763 #endif 764 765 if (nxt == IPPROTO_ROUTING) { 766 if (rh_present++) { 767 in6_ifstat_inc(m->m_pkthdr.rcvif, 768 ifs6_in_hdrerr); 769 ip6stat.ip6s_badoptions++; 770 goto bad; 771 } 772 } 773 774 sw6 = &inet6sw[ip6_protox[nxt]]; 775 #ifdef IPSEC 776 /* 777 * enforce IPsec policy checking if we are seeing last header. 778 * note that we do not visit this with protocols with pcb layer 779 * code - like udp/tcp/raw ip. 780 */ 781 if ((sw6->pr_flags & PR_LASTHDR) && ipsec6_in_reject(m, NULL)) { 782 ipsec6stat.in_polvio++; 783 goto bad; 784 } 785 #endif 786 /* 787 * If this is a terminal header forward to the port, otherwise 788 * process synchronously for more headers. 789 */ 790 if (sw6->pr_flags & PR_LASTHDR) { 791 struct netmsg_packet *pmsg; 792 lwkt_port_t port; 793 794 port = netisr_cpuport(0); /* XXX */ 795 KKASSERT(port != NULL); 796 pmsg = &m->m_hdr.mh_netmsg; 797 netmsg_init(&pmsg->base, NULL, 798 &netisr_apanic_rport, 799 0, transport6_processing_handler); 800 pmsg->nm_packet = m; 801 pmsg->nm_nxt = nxt; 802 pmsg->base.lmsg.u.ms_result = off; 803 lwkt_sendmsg(port, &pmsg->base.lmsg); 804 /* done with m */ 805 nxt = IPPROTO_DONE; 806 } else { 807 nxt = sw6->pr_input(&m, &off, nxt); 808 } 809 } 810 goto bad2; 811 bad: 812 m_freem(m); 813 bad2: 814 ; 815 /* msg was embedded in the mbuf, do not reply! */ 816 } 817 818 /* 819 * We have to call the pr_input() function from the correct protocol 820 * thread. The sw6->pr_soport() request at the end of ip6_input() 821 * returns the port and we forward a netmsg to the port to execute 822 * this function. 823 */ 824 static void 825 transport6_processing_handler(netmsg_t netmsg) 826 { 827 struct netmsg_packet *pmsg = (struct netmsg_packet *)netmsg; 828 struct protosw *sw6; 829 int hlen; 830 int nxt; 831 832 sw6 = &inet6sw[ip6_protox[pmsg->nm_nxt]]; 833 hlen = pmsg->base.lmsg.u.ms_result; 834 835 nxt = sw6->pr_input(&pmsg->nm_packet, &hlen, pmsg->nm_nxt); 836 KKASSERT(nxt == IPPROTO_DONE); 837 /* netmsg was embedded in the mbuf, do not reply! */ 838 } 839 840 /* 841 * set/grab in6_ifaddr correspond to IPv6 destination address. 842 * XXX backward compatibility wrapper 843 */ 844 static struct ip6aux * 845 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 846 { 847 struct ip6aux *n; 848 849 n = ip6_addaux(m); 850 if (n) 851 n->ip6a_dstia6 = ia6; 852 return n; /* NULL if failed to set */ 853 } 854 855 struct in6_ifaddr * 856 ip6_getdstifaddr(struct mbuf *m) 857 { 858 struct ip6aux *n; 859 860 n = ip6_findaux(m); 861 if (n) 862 return n->ip6a_dstia6; 863 else 864 return NULL; 865 } 866 867 /* 868 * Hop-by-Hop options header processing. If a valid jumbo payload option is 869 * included, the real payload length will be stored in plenp. 870 */ 871 static int 872 ip6_hopopts_input(u_int32_t *plenp, 873 u_int32_t *rtalertp,/* XXX: should be stored more smart way */ 874 struct mbuf **mp, 875 int *offp) 876 { 877 struct mbuf *m = *mp; 878 int off = *offp, hbhlen; 879 struct ip6_hbh *hbh; 880 881 /* validation of the length of the header */ 882 #ifndef PULLDOWN_TEST 883 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 884 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 885 hbhlen = (hbh->ip6h_len + 1) << 3; 886 887 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 888 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 889 #else 890 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 891 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 892 if (hbh == NULL) { 893 ip6stat.ip6s_tooshort++; 894 return -1; 895 } 896 hbhlen = (hbh->ip6h_len + 1) << 3; 897 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 898 hbhlen); 899 if (hbh == NULL) { 900 ip6stat.ip6s_tooshort++; 901 return -1; 902 } 903 #endif 904 off += hbhlen; 905 hbhlen -= sizeof(struct ip6_hbh); 906 907 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 908 hbhlen, rtalertp, plenp) < 0) 909 return (-1); 910 911 *offp = off; 912 *mp = m; 913 return (0); 914 } 915 916 /* 917 * Search header for all Hop-by-hop options and process each option. 918 * This function is separate from ip6_hopopts_input() in order to 919 * handle a case where the sending node itself process its hop-by-hop 920 * options header. In such a case, the function is called from ip6_output(). 921 * 922 * The function assumes that hbh header is located right after the IPv6 header 923 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 924 * opthead + hbhlen is located in continuous memory region. 925 */ 926 int 927 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 928 u_int32_t *rtalertp, u_int32_t *plenp) 929 { 930 struct ip6_hdr *ip6; 931 int optlen = 0; 932 u_int8_t *opt = opthead; 933 u_int16_t rtalert_val; 934 u_int32_t jumboplen; 935 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 936 937 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 938 switch (*opt) { 939 case IP6OPT_PAD1: 940 optlen = 1; 941 break; 942 case IP6OPT_PADN: 943 if (hbhlen < IP6OPT_MINLEN) { 944 ip6stat.ip6s_toosmall++; 945 goto bad; 946 } 947 optlen = *(opt + 1) + 2; 948 break; 949 case IP6OPT_RTALERT: 950 /* XXX may need check for alignment */ 951 if (hbhlen < IP6OPT_RTALERT_LEN) { 952 ip6stat.ip6s_toosmall++; 953 goto bad; 954 } 955 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 956 /* XXX stat */ 957 icmp6_error(m, ICMP6_PARAM_PROB, 958 ICMP6_PARAMPROB_HEADER, 959 erroff + opt + 1 - opthead); 960 return (-1); 961 } 962 optlen = IP6OPT_RTALERT_LEN; 963 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 964 *rtalertp = ntohs(rtalert_val); 965 break; 966 case IP6OPT_JUMBO: 967 /* XXX may need check for alignment */ 968 if (hbhlen < IP6OPT_JUMBO_LEN) { 969 ip6stat.ip6s_toosmall++; 970 goto bad; 971 } 972 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 973 /* XXX stat */ 974 icmp6_error(m, ICMP6_PARAM_PROB, 975 ICMP6_PARAMPROB_HEADER, 976 erroff + opt + 1 - opthead); 977 return (-1); 978 } 979 optlen = IP6OPT_JUMBO_LEN; 980 981 /* 982 * IPv6 packets that have non 0 payload length 983 * must not contain a jumbo payload option. 984 */ 985 ip6 = mtod(m, struct ip6_hdr *); 986 if (ip6->ip6_plen) { 987 ip6stat.ip6s_badoptions++; 988 icmp6_error(m, ICMP6_PARAM_PROB, 989 ICMP6_PARAMPROB_HEADER, 990 erroff + opt - opthead); 991 return (-1); 992 } 993 994 /* 995 * We may see jumbolen in unaligned location, so 996 * we'd need to perform bcopy(). 997 */ 998 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 999 jumboplen = (u_int32_t)htonl(jumboplen); 1000 1001 #if 1 1002 /* 1003 * if there are multiple jumbo payload options, 1004 * *plenp will be non-zero and the packet will be 1005 * rejected. 1006 * the behavior may need some debate in ipngwg - 1007 * multiple options does not make sense, however, 1008 * there's no explicit mention in specification. 1009 */ 1010 if (*plenp != 0) { 1011 ip6stat.ip6s_badoptions++; 1012 icmp6_error(m, ICMP6_PARAM_PROB, 1013 ICMP6_PARAMPROB_HEADER, 1014 erroff + opt + 2 - opthead); 1015 return (-1); 1016 } 1017 #endif 1018 1019 /* 1020 * jumbo payload length must be larger than 65535. 1021 */ 1022 if (jumboplen <= IPV6_MAXPACKET) { 1023 ip6stat.ip6s_badoptions++; 1024 icmp6_error(m, ICMP6_PARAM_PROB, 1025 ICMP6_PARAMPROB_HEADER, 1026 erroff + opt + 2 - opthead); 1027 return (-1); 1028 } 1029 *plenp = jumboplen; 1030 1031 break; 1032 default: /* unknown option */ 1033 if (hbhlen < IP6OPT_MINLEN) { 1034 ip6stat.ip6s_toosmall++; 1035 goto bad; 1036 } 1037 optlen = ip6_unknown_opt(opt, m, 1038 erroff + opt - opthead); 1039 if (optlen == -1) 1040 return (-1); 1041 optlen += 2; 1042 break; 1043 } 1044 } 1045 1046 return (0); 1047 1048 bad: 1049 m_freem(m); 1050 return (-1); 1051 } 1052 1053 /* 1054 * Unknown option processing. 1055 * The third argument `off' is the offset from the IPv6 header to the option, 1056 * which is necessary if the IPv6 header the and option header and IPv6 header 1057 * is not continuous in order to return an ICMPv6 error. 1058 */ 1059 int 1060 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1061 { 1062 struct ip6_hdr *ip6; 1063 1064 switch (IP6OPT_TYPE(*optp)) { 1065 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1066 return ((int)*(optp + 1)); 1067 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1068 m_freem(m); 1069 return (-1); 1070 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1071 ip6stat.ip6s_badoptions++; 1072 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1073 return (-1); 1074 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1075 ip6stat.ip6s_badoptions++; 1076 ip6 = mtod(m, struct ip6_hdr *); 1077 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1078 (m->m_flags & (M_BCAST|M_MCAST))) 1079 m_freem(m); 1080 else 1081 icmp6_error(m, ICMP6_PARAM_PROB, 1082 ICMP6_PARAMPROB_OPTION, off); 1083 return (-1); 1084 } 1085 1086 m_freem(m); /* XXX: NOTREACHED */ 1087 return (-1); 1088 } 1089 1090 /* 1091 * Create the "control" list for this pcb. 1092 * The function will not modify mbuf chain at all. 1093 * 1094 * with KAME mbuf chain restriction: 1095 * The routine will be called from upper layer handlers like tcp6_input(). 1096 * Thus the routine assumes that the caller (tcp6_input) have already 1097 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1098 * very first mbuf on the mbuf chain. 1099 */ 1100 void 1101 ip6_savecontrol(struct inpcb *in6p, struct mbuf **mp, struct ip6_hdr *ip6, 1102 struct mbuf *m) 1103 { 1104 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1105 struct thread *td = curthread; /* XXX */ 1106 int privileged = 0; 1107 1108 1109 if (priv_check(td, PRIV_ROOT) == 0) 1110 privileged++; 1111 1112 #ifdef SO_TIMESTAMP 1113 if (in6p->in6p_socket->so_options & SO_TIMESTAMP) { 1114 struct timeval tv; 1115 1116 microtime(&tv); 1117 *mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv), 1118 SCM_TIMESTAMP, SOL_SOCKET); 1119 if (*mp) { 1120 mp = &(*mp)->m_next; 1121 } 1122 } 1123 #endif 1124 1125 /* RFC 2292 sec. 5 */ 1126 if (in6p->in6p_flags & IN6P_PKTINFO) { 1127 struct in6_pktinfo pi6; 1128 1129 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1130 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1131 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) ? 1132 m->m_pkthdr.rcvif->if_index : 0; 1133 *mp = sbcreatecontrol((caddr_t)&pi6, sizeof(struct in6_pktinfo), 1134 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1135 if (*mp) 1136 mp = &(*mp)->m_next; 1137 } 1138 1139 if (in6p->in6p_flags & IN6P_HOPLIMIT) { 1140 int hlim = ip6->ip6_hlim & 0xff; 1141 1142 *mp = sbcreatecontrol((caddr_t)&hlim, sizeof(int), 1143 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1144 if (*mp) 1145 mp = &(*mp)->m_next; 1146 } 1147 1148 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1149 u_int32_t flowinfo; 1150 int tclass; 1151 1152 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1153 flowinfo >>= 20; 1154 1155 tclass = flowinfo & 0xff; 1156 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1157 IPV6_TCLASS, IPPROTO_IPV6); 1158 if (*mp) 1159 mp = &(*mp)->m_next; 1160 } 1161 1162 /* 1163 * IPV6_HOPOPTS socket option. We require super-user privilege 1164 * for the option, but it might be too strict, since there might 1165 * be some hop-by-hop options which can be returned to normal user. 1166 * See RFC 2292 section 6. 1167 */ 1168 if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) { 1169 /* 1170 * Check if a hop-by-hop options header is contatined in the 1171 * received packet, and if so, store the options as ancillary 1172 * data. Note that a hop-by-hop options header must be 1173 * just after the IPv6 header, which is assured through the 1174 * IPv6 input processing. 1175 */ 1176 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1177 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1178 struct ip6_hbh *hbh; 1179 int hbhlen = 0; 1180 #ifdef PULLDOWN_TEST 1181 struct mbuf *ext; 1182 #endif 1183 1184 #ifndef PULLDOWN_TEST 1185 hbh = (struct ip6_hbh *)(ip6 + 1); 1186 hbhlen = (hbh->ip6h_len + 1) << 3; 1187 #else 1188 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1189 ip6->ip6_nxt); 1190 if (ext == NULL) { 1191 ip6stat.ip6s_tooshort++; 1192 return; 1193 } 1194 hbh = mtod(ext, struct ip6_hbh *); 1195 hbhlen = (hbh->ip6h_len + 1) << 3; 1196 if (hbhlen != ext->m_len) { 1197 m_freem(ext); 1198 ip6stat.ip6s_tooshort++; 1199 return; 1200 } 1201 #endif 1202 1203 /* 1204 * XXX: We copy the whole header even if a 1205 * jumbo payload option is included, the option which 1206 * is to be removed before returning according to 1207 * RFC 2292. 1208 * Note: this constraint is removed in 2292bis. 1209 */ 1210 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1211 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1212 IPPROTO_IPV6); 1213 if (*mp) 1214 mp = &(*mp)->m_next; 1215 #ifdef PULLDOWN_TEST 1216 m_freem(ext); 1217 #endif 1218 } 1219 } 1220 1221 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1222 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1223 int proto, off, nxt; 1224 1225 /* 1226 * go through the header chain to see if a routing header is 1227 * contained in the packet. We need this information to store 1228 * destination options headers (if any) properly. 1229 * XXX: performance issue. We should record this info when 1230 * processing extension headers in incoming routine. 1231 * (todo) use m_aux? 1232 */ 1233 proto = IPPROTO_IPV6; 1234 off = 0; 1235 nxt = -1; 1236 while (1) { 1237 int newoff; 1238 1239 newoff = ip6_nexthdr(m, off, proto, &nxt); 1240 if (newoff < 0) 1241 break; 1242 if (newoff < off) /* invalid, check for safety */ 1243 break; 1244 if ((proto = nxt) == IPPROTO_ROUTING) 1245 break; 1246 off = newoff; 1247 } 1248 } 1249 1250 if ((in6p->in6p_flags & 1251 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1252 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1253 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1254 1255 /* 1256 * Search for destination options headers or routing 1257 * header(s) through the header chain, and stores each 1258 * header as ancillary data. 1259 * Note that the order of the headers remains in 1260 * the chain of ancillary data. 1261 */ 1262 while (1) { /* is explicit loop prevention necessary? */ 1263 struct ip6_ext *ip6e = NULL; 1264 int elen; 1265 #ifdef PULLDOWN_TEST 1266 struct mbuf *ext = NULL; 1267 #endif 1268 1269 /* 1270 * if it is not an extension header, don't try to 1271 * pull it from the chain. 1272 */ 1273 switch (nxt) { 1274 case IPPROTO_DSTOPTS: 1275 case IPPROTO_ROUTING: 1276 case IPPROTO_HOPOPTS: 1277 case IPPROTO_AH: /* is it possible? */ 1278 break; 1279 default: 1280 goto loopend; 1281 } 1282 1283 #ifndef PULLDOWN_TEST 1284 if (off + sizeof(*ip6e) > m->m_len) 1285 goto loopend; 1286 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1287 if (nxt == IPPROTO_AH) 1288 elen = (ip6e->ip6e_len + 2) << 2; 1289 else 1290 elen = (ip6e->ip6e_len + 1) << 3; 1291 if (off + elen > m->m_len) 1292 goto loopend; 1293 #else 1294 ext = ip6_pullexthdr(m, off, nxt); 1295 if (ext == NULL) { 1296 ip6stat.ip6s_tooshort++; 1297 return; 1298 } 1299 ip6e = mtod(ext, struct ip6_ext *); 1300 if (nxt == IPPROTO_AH) 1301 elen = (ip6e->ip6e_len + 2) << 2; 1302 else 1303 elen = (ip6e->ip6e_len + 1) << 3; 1304 if (elen != ext->m_len) { 1305 m_freem(ext); 1306 ip6stat.ip6s_tooshort++; 1307 return; 1308 } 1309 #endif 1310 1311 switch (nxt) { 1312 case IPPROTO_DSTOPTS: 1313 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0) 1314 break; 1315 1316 /* 1317 * We also require super-user privilege for 1318 * the option. See comments on IN6_HOPOPTS. 1319 */ 1320 if (!privileged) 1321 break; 1322 1323 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1324 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1325 IPPROTO_IPV6); 1326 if (*mp) 1327 mp = &(*mp)->m_next; 1328 break; 1329 case IPPROTO_ROUTING: 1330 if (!(in6p->in6p_flags & IN6P_RTHDR)) 1331 break; 1332 1333 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1334 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1335 IPPROTO_IPV6); 1336 if (*mp) 1337 mp = &(*mp)->m_next; 1338 break; 1339 case IPPROTO_HOPOPTS: 1340 case IPPROTO_AH: /* is it possible? */ 1341 break; 1342 1343 default: 1344 /* 1345 * other cases have been filtered in the above. 1346 * none will visit this case. here we supply 1347 * the code just in case (nxt overwritten or 1348 * other cases). 1349 */ 1350 #ifdef PULLDOWN_TEST 1351 m_freem(ext); 1352 #endif 1353 goto loopend; 1354 1355 } 1356 1357 /* proceed with the next header. */ 1358 off += elen; 1359 nxt = ip6e->ip6e_nxt; 1360 ip6e = NULL; 1361 #ifdef PULLDOWN_TEST 1362 m_freem(ext); 1363 ext = NULL; 1364 #endif 1365 } 1366 loopend: 1367 ; 1368 } 1369 #undef IS2292 1370 } 1371 1372 void 1373 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1374 { 1375 struct socket *so; 1376 struct mbuf *m_mtu; 1377 struct ip6_mtuinfo mtuctl; 1378 1379 so = in6p->inp_socket; 1380 1381 if (mtu == NULL) 1382 return; 1383 1384 #ifdef DIAGNOSTIC 1385 if (so == NULL) /* I believe this is impossible */ 1386 panic("ip6_notify_pmtu: socket is NULL"); 1387 #endif 1388 1389 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1390 mtuctl.ip6m_mtu = *mtu; 1391 mtuctl.ip6m_addr = *dst; 1392 1393 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1394 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1395 return; 1396 1397 lwkt_gettoken(&so->so_rcv.ssb_token); 1398 if (sbappendaddr(&so->so_rcv.sb, (struct sockaddr *)dst, NULL, m_mtu) 1399 == 0) { 1400 m_freem(m_mtu); 1401 /* XXX: should count statistics */ 1402 } else { 1403 sorwakeup(so); 1404 } 1405 lwkt_reltoken(&so->so_rcv.ssb_token); 1406 } 1407 1408 #ifdef PULLDOWN_TEST 1409 /* 1410 * pull single extension header from mbuf chain. returns single mbuf that 1411 * contains the result, or NULL on error. 1412 */ 1413 static struct mbuf * 1414 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1415 { 1416 struct ip6_ext ip6e; 1417 size_t elen; 1418 struct mbuf *n; 1419 1420 #ifdef DIAGNOSTIC 1421 switch (nxt) { 1422 case IPPROTO_DSTOPTS: 1423 case IPPROTO_ROUTING: 1424 case IPPROTO_HOPOPTS: 1425 case IPPROTO_AH: /* is it possible? */ 1426 break; 1427 default: 1428 kprintf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1429 } 1430 #endif 1431 1432 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1433 if (nxt == IPPROTO_AH) 1434 elen = (ip6e.ip6e_len + 2) << 2; 1435 else 1436 elen = (ip6e.ip6e_len + 1) << 3; 1437 1438 n = m_getb(elen, M_NOWAIT, MT_DATA, 0); 1439 if (n == NULL) 1440 return NULL; 1441 n->m_len = 0; 1442 1443 if (elen >= M_TRAILINGSPACE(n)) { 1444 m_free(n); 1445 return NULL; 1446 } 1447 1448 m_copydata(m, off, elen, mtod(n, caddr_t)); 1449 n->m_len = elen; 1450 return n; 1451 } 1452 #endif 1453 1454 /* 1455 * Get pointer to the previous header followed by the header 1456 * currently processed. 1457 * XXX: This function supposes that 1458 * M includes all headers, 1459 * the next header field and the header length field of each header 1460 * are valid, and 1461 * the sum of each header length equals to OFF. 1462 * Because of these assumptions, this function must be called very 1463 * carefully. Moreover, it will not be used in the near future when 1464 * we develop `neater' mechanism to process extension headers. 1465 */ 1466 char * 1467 ip6_get_prevhdr(struct mbuf *m, int off) 1468 { 1469 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1470 1471 if (off == sizeof(struct ip6_hdr)) 1472 return (&ip6->ip6_nxt); 1473 else { 1474 int len, nxt; 1475 struct ip6_ext *ip6e = NULL; 1476 1477 nxt = ip6->ip6_nxt; 1478 len = sizeof(struct ip6_hdr); 1479 while (len < off) { 1480 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1481 1482 switch (nxt) { 1483 case IPPROTO_FRAGMENT: 1484 len += sizeof(struct ip6_frag); 1485 break; 1486 case IPPROTO_AH: 1487 len += (ip6e->ip6e_len + 2) << 2; 1488 break; 1489 default: 1490 len += (ip6e->ip6e_len + 1) << 3; 1491 break; 1492 } 1493 nxt = ip6e->ip6e_nxt; 1494 } 1495 if (ip6e) 1496 return (&ip6e->ip6e_nxt); 1497 else 1498 return NULL; 1499 } 1500 } 1501 1502 /* 1503 * get next header offset. m will be retained. 1504 */ 1505 int 1506 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1507 { 1508 struct ip6_hdr ip6; 1509 struct ip6_ext ip6e; 1510 struct ip6_frag fh; 1511 1512 /* just in case */ 1513 if (m == NULL) 1514 panic("ip6_nexthdr: m == NULL"); 1515 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1516 return -1; 1517 1518 switch (proto) { 1519 case IPPROTO_IPV6: 1520 if (m->m_pkthdr.len < off + sizeof(ip6)) 1521 return -1; 1522 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1523 if (nxtp) 1524 *nxtp = ip6.ip6_nxt; 1525 off += sizeof(ip6); 1526 return off; 1527 1528 case IPPROTO_FRAGMENT: 1529 /* 1530 * terminate parsing if it is not the first fragment, 1531 * it does not make sense to parse through it. 1532 */ 1533 if (m->m_pkthdr.len < off + sizeof(fh)) 1534 return -1; 1535 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1536 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1537 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1538 return -1; 1539 if (nxtp) 1540 *nxtp = fh.ip6f_nxt; 1541 off += sizeof(struct ip6_frag); 1542 return off; 1543 1544 case IPPROTO_AH: 1545 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1546 return -1; 1547 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1548 if (nxtp) 1549 *nxtp = ip6e.ip6e_nxt; 1550 off += (ip6e.ip6e_len + 2) << 2; 1551 return off; 1552 1553 case IPPROTO_HOPOPTS: 1554 case IPPROTO_ROUTING: 1555 case IPPROTO_DSTOPTS: 1556 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1557 return -1; 1558 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1559 if (nxtp) 1560 *nxtp = ip6e.ip6e_nxt; 1561 off += (ip6e.ip6e_len + 1) << 3; 1562 return off; 1563 1564 case IPPROTO_NONE: 1565 case IPPROTO_ESP: 1566 case IPPROTO_IPCOMP: 1567 /* give up */ 1568 return -1; 1569 1570 default: 1571 return -1; 1572 } 1573 1574 return -1; 1575 } 1576 1577 /* 1578 * get offset for the last header in the chain. m will be kept untainted. 1579 */ 1580 int 1581 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1582 { 1583 int newoff; 1584 int nxt; 1585 1586 if (!nxtp) { 1587 nxt = -1; 1588 nxtp = &nxt; 1589 } 1590 while (1) { 1591 newoff = ip6_nexthdr(m, off, proto, nxtp); 1592 if (newoff < 0) 1593 return off; 1594 else if (newoff < off) 1595 return -1; /* invalid */ 1596 else if (newoff == off) 1597 return newoff; 1598 1599 off = newoff; 1600 proto = *nxtp; 1601 } 1602 } 1603 1604 struct ip6aux * 1605 ip6_addaux(struct mbuf *m) 1606 { 1607 struct m_tag *mtag; 1608 1609 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1610 if (!mtag) { 1611 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1612 M_NOWAIT); 1613 if (mtag) 1614 m_tag_prepend(m, mtag); 1615 } 1616 if (mtag) 1617 bzero(m_tag_data(mtag), sizeof(struct ip6aux)); 1618 return mtag ? (struct ip6aux *)m_tag_data(mtag) : NULL; 1619 } 1620 1621 struct ip6aux * 1622 ip6_findaux(struct mbuf *m) 1623 { 1624 struct m_tag *mtag; 1625 1626 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1627 return mtag ? (struct ip6aux *)m_tag_data(mtag) : NULL; 1628 } 1629 1630 void 1631 ip6_delaux(struct mbuf *m) 1632 { 1633 struct m_tag *mtag; 1634 1635 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1636 if (mtag) 1637 m_tag_delete(m, mtag); 1638 } 1639 1640 /* 1641 * System control for IP6 1642 */ 1643 1644 u_char inet6ctlerrmap[PRC_NCMDS] = { 1645 0, 0, 0, 0, 1646 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1647 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1648 EMSGSIZE, EHOSTUNREACH, 0, 0, 1649 0, 0, 0, 0, 1650 ENOPROTOOPT 1651 }; 1652